U.S. authorities are working to determine whether the suspect in Saturday's bombings in New York City and New Jersey has any foreign terror ties and what may have motivated the attack that wounded 29 people.

Police arrested Ahmad Khan Rahami, 28, on Monday after a search they said focused on him because he was spotted on surveillance video at the blast site and another nearby location where a similar bomb was found but did not explode. Investigators also said they found fingerprint and DNA evidence.

Rahami has been charged with five counts of attempted murder in connection with an exchange of gunfire he had with officers who confronted and arrested him in Linden, New Jersey, just west of New York. A bar owner there had found Rahami sleeping in a doorway and called police.

Federal prosecutors have not yet filed any charges for the bombing itself.

Link to New Jersey blast

Linden is about 5 kilometers from the town of Elizabeth where on Sunday police were alerted to a backpack containing several explosive devices, one of which went off as a robot tried to defuse it. That discovery was made close to a restaurant run by Rahami's family.

Authorities also suspect Rahami was behind an explosion in a trash can at a charity running race Saturday morning in Seaside Park, New Jersey, about 130 kilometers south of New York. No one was hurt in that blast.

New York City Mayor Bill de Blasio said Monday that Rahami was the only suspect so far, and that there was every reason to believe the bombings were acts of terrorism.

Obama: 'Be vigilant and aggressive' to prevent senseless violence

President Barack Obama, who was in New York along with other world leaders for the United Nations General Assembly, said terrorists want to hurt innocent people, inspire fear and disrupt the way people live.

"We have to be vigilant and aggressive, both on preventing senseless acts of violence but also making sure that we find those who carry out such acts and bring them to justice. We all have a role to play as citizens in making sure that we don't succumb to that fear."

One New Yorker told VOA that the bombing was unsettling but not surprising.

"There is a security to this city. Sure there are days where I have my doubts about that, but because I do feel this camaraderie in the city, I do feel relatively safe," she said.

Federal Bureau of Investigation personnel search an address during an investigation into Ahmad Khan Rahami, who was wanted for questioning in an explosion in New York, which authorities believe is linked to the explosive devices found in New Jersey, Sept. 19, 2016.

Naturalized US citizen

Suspected bomber Rahami was born in Afghanistan and is a naturalized U.S. citizen.

Some of the customers from his family's restaurant said they are shocked that Rahami is a suspect, calling him friendly. They say he let local bands practice in the back of the store, and gave them free food.